Zero cooling water control method and dual-purpose furnace system

Abstract

The present invention discloses a zero cold water control method and a dual-purpose furnace system, which relates to the field of household stoves. The zero cold water control method comprises the following steps: S1, judging the mode of the dual-purpose furnace system, if the dual-purpose furnace system is in winter mode, executing step S2; S2, judging whether the water flow is circulating in the heating circuit; if so, executing step S3; S3, after the circulation of the heating circuit is completed, the water flow is switched to the domestic water heating circuit, and the domestic water circuit is continuously heated for the first set time T1; S4, detecting the time T of the water flow circulation in the domestic water heating circuit, if T is greater than the first set time T1 and less than or equal to the second set time T2, executing step S5; S5, detecting the water inlet temperature H1 of the domestic water circuit, if H1 satisfies: H1≥H0-ΔH1, then closing the domestic water heating circuit; wherein, H0 is the set temperature of zero cold water heating, and ΔH1 is the first stop deviation value. The present invention can avoid the influence of the heating circuit on zero cold water heating.

Description

Technical Field

[0001] The invention relates to the field of household stoves, and in particular to a zero-cold-water control method and a dual-purpose stove system. Background Art

[0002] Some households use non-central heating, which requires heating water through household stoves and circulating it for heating. Dual-purpose stoves that can bear the heat load of both domestic water and household heating water have become the first choice for non-central heating users.

[0003] The hot water pipeline of the dual-purpose boiler is divided into two parts. One part is a closed heating loop, where hot water circulates in the indoor pipes to heat the indoor environment, and the other part is a domestic water loop, where hot water can flow out directly for domestic use. Currently, dual-purpose boiler products with zero cold water function on the market determine whether to turn on the zero cold water function by detecting the difference between the domestic inlet / outlet water temperature sensor and the set temperature.

[0004] Due to the spatial layout of the dual-purpose furnace, when the whole machine performs heating, the hot water in the heating circuit will increase the value of the domestic water outlet temperature sensor through heat conduction, making it difficult to enter the zero cold water function next time, and users will use cold water. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defect of misjudgment of zero cold water function caused by heating of the heating circuit in the prior art, and to provide a zero cold water control method and a dual-purpose furnace system.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] According to a first aspect of the present invention, there is provided a zero cooling water control method for a dual-purpose furnace system, the dual-purpose furnace system comprising a heating circuit, a domestic water heating circuit and a domestic water circuit, the heating circuit being used to heat the external environment, the domestic water heating circuit being used to heat water in the domestic water circuit;

[0008] The dual-purpose furnace system has a summer mode and a winter mode. When the dual-purpose furnace system is in the summer mode, the heating circuit is always kept closed; when the dual-purpose furnace system is in the winter mode, the water flow can be switched between the heating circuit and the domestic water heating circuit.

[0009] The zero cooling water control method includes the following steps:

[0010] S1, determine the mode of the dual-purpose furnace system. If the dual-purpose furnace system is in the winter mode, execute step S2;

[0011] S2, determine whether the water flow is circulating in the heating circuit; if so, execute step S3;

[0012] S3, after the circulation of the heating circuit is completed, the water flow is switched to the domestic water heating circuit, and the domestic water circuit is continuously heated for the first set time T1;

[0013] S4, detecting the water circulation time T in the domestic water heating circuit, and if T is greater than the first set time T1, executing step S5;

[0014] S5. Detect the water inlet temperature H1 of the domestic water circuit. If H1 satisfies: H1≥H0-ΔH1, close the domestic water heating circuit; wherein H0 is the set temperature for zero cold water heating, and ΔH1 is the first stop deviation value.

[0015] In this solution, the dual-purpose furnace system provides heating to the outside through the heating circuit and heats the domestic water circuit through the domestic water heating circuit. When the dual-purpose furnace system is in winter mode, the domestic water heating circuit is forced to heat for the first set time after the heating circuit cycle ends, so as to avoid stopping the zero cold water circulation after the domestic water circuit partially rises in temperature due to heat conduction of the heating circuit or uneven heating of the domestic water heating circuit, thereby ensuring that the domestic water circuit can start the zero cold water circulation to heat to a certain temperature, and avoid the zero cold water heating function failing to start due to the partial temperature rise of the domestic water circuit caused by heat conduction of the heating circuit ; During the time period from T1 to T2, determine whether to exit zero cold water heating based on the domestic water inlet temperature H1. Since the domestic water inlet temperature H1 is the lowest water temperature in the domestic water circuit, and the domestic water inlet temperature H1 meets the demand, the temperature of the domestic water circuit meets the conditions for exiting zero cold water heating; therefore, through the above-mentioned control method, determine whether to exit zero cold water heating based on the heating time and the domestic water inlet temperature, and associate the zero cold water heating with whether the heating circuit is connected, thereby achieving precise control of zero cold water heating, avoiding the influence of the heating circuit on zero cold water heating, and ensuring that the temperature of the zero cold water circulation meets the standard.

[0016] Preferably, in step S4, if T is greater than the first set time T1 and less than or equal to the second set time T2, step S5 is executed.

[0017] In this scheme, step S5 is executed when the water flow circulation time T is greater than T1 and less than or equal to T2, that is, in the time period from T1 to T2, the water in the domestic water circuit has not been heated yet, so the water inlet temperature H1 (the lowest water temperature in the domestic water circuit) is used to judge whether the water temperature in the domestic water circuit meets the demand, thereby judging whether to exit zero cold water heating; when T is greater than T2, the water in the domestic water circuit has been continuously heated for a period of time. At this time, the temperature of other points can be used to judge whether to exit zero cold water heating, and it is no longer limited to the control method in step S5.

[0018] Preferably, in step S2, if it is determined that the water flow does not circulate in the heating circuit and either H1 < H0 - Hd1 or H2 < H0 - Hd2 is satisfied, then switch to the domestic hot water heating circuit; otherwise, the domestic hot water heating circuit remains closed; where H1 is the inlet water temperature of the domestic hot water circuit, H2 is the outlet water temperature of the domestic hot water circuit, Hd1 is the first start-up deviation value, and Hd2 is the second start-up deviation value.

[0019] In this solution, in winter mode, if the heating circuit is not started, the domestic hot water circuit will not be affected by the heating circuit. At this time, it can be determined whether to start zero cold water heating according to the difference between the inlet water temperature H1 of the domestic hot water circuit or the outlet water temperature H2 of the domestic hot water circuit and the set temperature H0 of zero cold water heating. When the difference between H0 and H1 is greater than Hd1, or the difference between H0 and H2 is greater than Hd2, it means that the water temperature in the domestic hot water circuit is significantly lower than the set temperature, and zero cold water heating needs to be started.

[0020] Preferably, in step S2, the first start-up deviation value Hd1 > the second start-up deviation value Hd2.

[0021] In this solution, in the domestic hot water circuit, after the water enters the domestic hot water circuit, it is heated by the domestic hot water heating circuit and then exits. The inlet water temperature of the domestic hot water circuit is low, while the outlet water temperature of the domestic hot water circuit is high. Therefore, Hd1 > Hd2, that is, H1 can be relatively lower than H2, so as to more accurately control the opening of the zero cold water circuit.

[0022] Preferably, in step S3, if H3 - H4 > Hq, then close the heating circuit and end the heating; where H3 is the outlet water temperature of the heating circuit, H4 is the set outlet water temperature of the heating circuit, and Hq is the set temperature threshold.

[0023] In this solution, it is determined whether to close the heating circuit according to the difference between the outlet water temperature H3 of the heating circuit and the set outlet water temperature H4 of the heating circuit. When the difference between H3 and H4 is greater than the set temperature threshold, the water temperature in the heating circuit drops less, and the external heating demand has been met. At this time, the circulation of the heating circuit can be stopped and the heating circuit can be closed.

[0024] Preferably, in step S1, if the dual-purpose furnace system is in summer mode, then perform the following steps:

[0025] If either H1 < H0 - Hd1 or H2 < H0 - Hd2 is satisfied, then switch to the domestic hot water heating circuit; otherwise, the domestic hot water heating circuit remains closed; where H1 is the inlet water temperature of the domestic hot water circuit, H2 is the outlet water temperature of the domestic hot water circuit, Hd1 is the first start-up deviation value, and Hd2 is the second start-up deviation value.

[0026] In this solution, when the dual-purpose boiler system is in summer mode, since there is no need for heating through the dual-purpose boiler system, the domestic water circuit will not be affected by the heating circuit. Therefore, whether to start zero cold water heating can be directly judged based on the inlet water temperature H1 or the outlet water temperature H2 of the domestic water circuit. When the difference between H0 and H1 is greater than Hd1, or the difference between H0 and H2 is greater than Hd2, it means that the water temperature in the domestic water circuit is already significantly lower than the set temperature, and zero cold water heating needs to be started.

[0027] Preferably, in step S3, the first set time T1 is 1 minute.

[0028] In this solution, after the heating circuit ends the circulation, the domestic water heating circuit is forced to start for 1 minute to ensure that the water in the domestic water circuit can be heated to a certain degree, so as to avoid the failure to start zero cold water heating due to the rise of water temperature in the domestic water circuit caused by the heat conduction of the heating circuit. If T1 is too large, it is easy to cause the water temperature in the domestic water circuit to be too high. It has been verified that the best effect is when T1 is 1 minute.

[0029] Preferably, in step S4, if the circulation time of the domestic water heating circuit is greater than the second set time T2, the following steps are performed:

[0030] Detect the water inlet temperature H1 and the water outlet temperature H2 of the domestic water circuit. If any one of H1≥H0-ΔH1 and H2≥H0+ΔH2 is satisfied, close the domestic water heating circuit; wherein ΔH1 is the first stop deviation value, and ΔH2 is the second stop deviation value.

[0031] In this scheme, when the zero cold water heating time T>T2, since the domestic water circuit has been heated continuously for a period of time, the water temperature in the domestic water circuit is relatively balanced. At this time, only one of the domestic water inlet temperature H1 and the domestic water outlet temperature H2 needs to meet the corresponding set conditions (that is, H1≥H0-ΔH1 or H2≥H0+ΔH2) to exit the zero cold water heating, thereby avoiding excessive water temperature in the domestic water circuit and making the zero cold water heating control more accurate and reliable.

[0032] Preferably, the first stop deviation value ΔH1 is equal to the second stop deviation value ΔH2.

[0033] In this solution, the first stop deviation value ΔH1 is equal to the second stop deviation value ΔH2, that is, the difference between H0 and H1 is equal to the difference between H2 and H0, ensuring that the water temperature in the domestic water circuit is relatively uniform.

[0034] According to a second aspect of the present invention, there is provided a dual-purpose furnace system, wherein the dual-purpose furnace system applies the above zero cooling water control method.

[0035] In this solution, the dual-purpose furnace system applies the above-mentioned zero cold water control method, which can effectively avoid the impact on the zero cold water circulation of domestic water during heating, and improve the accuracy and reliability of zero cold water heating control.

[0036] The positive and progressive effects of the present invention are:

[0037] When the dual-purpose furnace system of the present invention is in winter mode, the domestic water heating circuit is forced to heat for the first set time after the heating circuit circulation ends, so as to avoid stopping the zero cold water circulation after the domestic water circuit partially rises in temperature due to heat conduction of the heating circuit or uneven heating of the domestic water heating circuit, and avoid the zero cold water heating function being unable to start due to the partial temperature rise of the domestic water circuit caused by heat conduction of the heating circuit; determine whether to exit the zero cold water heating according to the heating time and the inlet temperature of the domestic water, and associate the zero cold water heating with whether the heating circuit is connected, so as to realize precise control of the zero cold water heating, avoid the influence of the heating circuit on the zero cold water heating, and ensure that the temperature of the zero cold water circulation meets the standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of a dual-purpose furnace system according to an embodiment of the present invention.

[0039] Figure 2 This is a control flow chart of a zero cooling water control method according to an embodiment of the present invention.

[0040] Description of reference numerals:

[0041] Dual-purpose furnace system 100

[0042] Heating return pipe 110

[0043] Heater 120

[0044] Heating water outlet pipe 130

[0045] Circulation pipe 140

[0046] Heat exchanger 150

[0047] Domestic water inlet pipe 160

[0048] Domestic water pipe 170

[0049] Zero cold water pipe 180

[0050] Switching valve 200

[0051] First circulation pump 300

[0052] Second circulation pump 400

[0053] Heating return water temperature sensor 500

[0054] Heating water temperature sensor 600

[0055] Domestic water inlet temperature sensor 700

[0056] Domestic water temperature sensor 800

[0057] Water supply 101

[0058] Water end 102 DETAILED DESCRIPTION

[0059] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0060] This embodiment discloses a dual-purpose furnace system 100, referring to Figure 1 The dual-purpose furnace system 100 includes a heating circuit, a domestic water heating circuit, a switching valve 200, a domestic water circuit and a controller. The heating circuit is used to heat the external environment, the domestic water circuit is used to provide domestic water, the domestic water heating circuit is used to heat water in the domestic water circuit, and the switching valve 200 is used to control the switching of water flow between the heating circuit and the domestic water heating circuit. The controller is used to control the switching of the heating circuit and the domestic water heating circuit according to time and temperature.

[0061] The heating circuit includes a heating return pipe 110, a heater 120 and a heating outlet pipe 130. The heating return pipe 110, the heater 120, the heating outlet pipe 130 and the heating return pipe 110 are connected in sequence to form a circuit. When the heating circuit is connected, water with a lower temperature flows from the heating return pipe 110 into the heater 120 for heating, becomes water with a higher temperature and flows out through the heating outlet pipe 130 to exchange heat with the external environment for heating, and then flows back to the heater 120 through the heating return pipe 110 for heating after the temperature is reduced, completing the circulation in the heating circuit.

[0062] The domestic water heating circuit includes a partial heating return pipe 110, a heater 120, a partial heating outlet pipe 130, a circulation pipe 140 and a heat exchanger 150. The partial heating return pipe 110, the heater 120, the partial heating outlet pipe 130, the circulation pipe 140 and the partial heating return pipe 110 are sequentially connected to form a circuit that is smaller than the heating circuit, and the heat exchanger 150 is arranged on the circulation pipe 140. When the domestic water heating circuit is connected, water with a relatively low temperature flows from the partial heating return pipe 110 into the heater 120, is heated by the heater 120 and flows into the partial heating outlet pipe 130, then flows through the circulation pipe 140 and the heat exchanger 150 to exchange heat with the domestic water circuit to reduce the temperature, and finally flows into the heater 120 through the heating return pipe 110 and is heated again, completing the circulation in the domestic water heating circuit.

[0063] The switching valve 200 is arranged on the heating circuit and / or the domestic water heating circuit and is electrically connected to the controller. The controller controls the switching of the switching valve 200 to switch, thereby switching the water flow in the heating circuit and / or the domestic water heating circuit. Specifically, in the present embodiment, the switching valve 200 is a three-way valve, one port of the switching valve 200 is connected to the circulation pipe 140, and the other two ports of the switching valve 200 are connected to the heating outlet pipe 130. By controlling the connectivity of the three ports of the switching valve 200, the water flow in the heating circuit and / or the domestic water heating circuit is controlled. In addition, in other embodiments, the switching valve 200 may also be a valve of other forms, and the switching valve 200 may also be one or more groups of valves.

[0064] The dual-purpose furnace system 100 also includes a first circulation pump 300, which is arranged on the heating circuit and / or the domestic water heating circuit and is electrically connected to the controller, and is used to drive the water flow to circulate in the heating circuit and / or the domestic water heating circuit. In this embodiment, the first circulation pump 300 is arranged on a portion of the heating return pipe 110 in the domestic water heating circuit, so that only one common first circulation pump 300 is required to drive the water flow to circulate in the heating circuit and / or the domestic water heating circuit. In addition, in other embodiments, the first circulation pump 300 can be independently arranged on the heating circuit and the domestic water heating circuit.

[0065] In this embodiment, a heating return water temperature sensor 500 is provided on the heating return water pipe 110, and a heating outlet water temperature sensor 600 is provided on the heating outlet water pipe 130. The heating return water temperature sensor 500 and the heating outlet water temperature sensor 600 are both electrically connected to the controller. The heating return water temperature sensor 500 is used to measure the water temperature in the heating return water pipe 110, and the heating outlet water temperature sensor 600 is used to measure the water temperature in the heating outlet water pipe 130, so that the controller can judge the heating situation according to the temperature of the heating circuit.

[0066] The domestic water loop includes a domestic water inlet pipe 160, a domestic water outlet pipe 170 and a zero-cold water pipe 180. The domestic water inlet pipe 160 is connected to the water supply end 101, the domestic water outlet pipe 170 is connected to the water use end 102, and the domestic water inlet pipe 160, the domestic water outlet pipe 170, the zero-cold water pipe 180 and the domestic water inlet pipe 160 are sequentially connected to form a loop. One connecting end of the domestic water inlet pipe 160 and the domestic water outlet pipe 170 is located in the heat exchanger 150 and can exchange heat with the heat exchanger 150. As a result, the water with a lower temperature in the domestic water inlet pipe 160 flows into the domestic water outlet pipe 170 after being heated by the heat exchanger 150, and can flow out to the water use end 102 through the domestic water outlet pipe 170 for use by users.

[0067] The domestic water loop also includes a second circulation pump 400, which is arranged on one or more of the domestic water inlet pipe 160, the domestic water outlet pipe 170 and the zero cold water pipe 180 and is electrically connected to the controller to drive water to circulate in the domestic water loop. Specifically, in this embodiment, one second circulation pump 400 is arranged on the domestic water inlet pipe 160. Thus, when the user does not use water, the water end 102 is closed, and the controller controls the second circulation pump 400 according to the water temperature to drive the water to circulate in the domestic water loop, and heats it through the heat exchanger 150 to achieve the effect of zero cold water.

[0068] A domestic water inlet temperature sensor 700 is provided on the domestic water inlet pipe 160 , and a domestic water outlet temperature sensor 800 is provided on the domestic water outlet pipe 170 . Both the domestic water inlet temperature sensor 700 and the domestic water outlet temperature sensor 800 are electrically connected to the controller.

[0069] In this embodiment, the dual-purpose furnace system 100 has a summer mode and a winter mode. Specifically, the summer mode and the winter mode can be designed according to the season or temperature. When the dual-purpose furnace system 100 is in the summer mode, the dual-purpose furnace system 100 does not need to bear the heating heat load, and the heating circuit is always kept closed; when the dual-purpose furnace system 100 is in the winter mode, the dual-purpose furnace system 100 bears the heating heat load and the domestic water heat load, and the water flow can be switched between the heating circuit and the domestic water heating circuit.

[0070] This embodiment also discloses a zero cold water control method. The dual-purpose furnace system 100 is controlled by the zero cold water control method, which can effectively avoid the impact of zero cold water circulation on domestic water during heating, and improve the accuracy and reliability of zero cold water heating control.

[0071] Reference Figure 2 The zero cooling water control method of the dual-purpose furnace system 100 comprises the following steps:

[0072] S1, determining the mode of the dual-purpose furnace system 100, if the dual-purpose furnace system 100 is in the winter mode, executing step S2;

[0073] Step S1 includes the following steps:

[0074] S11, determine the mode of the dual-purpose stove system 100. If the dual-purpose stove system 100 is in the winter mode, execute step S2; otherwise, the dual-purpose stove system 100 is in the summer mode, execute step S12:

[0075] S12. If either H1 < H0 - Hd1 or H2 < H0 - Hd2 is satisfied, then execute step S32; otherwise, return to step S11. Here, H1 is the inlet water temperature detected by the domestic water inlet temperature sensor 700, H2 is the outlet water temperature detected by the domestic water outlet temperature sensor 800, Hd1 is the first start-up deviation value, and Hd2 is the second start-up deviation value. Here, H0 is the set temperature for zero cold water heating, and this set temperature H0 can be the outlet water temperature input by the user at the outlet end of the dual-purpose furnace system, or the desired temperature in the domestic water circuit preset in the system.

[0076] Hd1 and Hd2 can be designed according to the actual situation. In this embodiment, Hd1 is 10°C and Hd2 is 5°C.

[0077] Specifically, the summer mode and winter mode can be designed according to the season or temperature. When the dual-purpose furnace system 100 is in the summer mode, since there is no need to use the dual-purpose furnace system 100 for heating, the domestic water circuit will not be affected by the heating circuit. Therefore, it is possible to directly determine whether to start zero cold water heating based on the inlet water temperature H1 or the outlet water temperature H2 of the domestic water circuit. When either the difference between H0 and H1 is greater than Hd1 or the difference between H0 and H2 is greater than Hd2, it indicates that the water temperature in the domestic water circuit has dropped significantly below the set temperature, and zero cold water heating is started.

[0078] S2. According to the port connection status of the switching valve 200, determine whether the water flow is circulating in the heating circuit. If so, execute step S3; otherwise, execute step S12.

[0079] In this embodiment, in the winter mode, if the heating function is not started and the heating circuit is closed, the domestic water circuit will not be affected by the heating circuit. At this time, it is possible to determine whether to start zero cold water heating based on the difference between the inlet water temperature H1 or the outlet water temperature H2 of the domestic water circuit and the set temperature H0 for zero cold water heating. When either the difference between H0 and H1 is greater than Hd1 or the difference between H0 and H2 is greater than Hd2, it indicates that the water temperature in the domestic water circuit has dropped significantly below the set temperature, and zero cold water heating needs to be started.

[0080] Among them, the first start-up deviation value Hd1 > the second start-up deviation value Hd2. Since after the domestic water circuit takes in water, it is heated by the domestic water heating circuit and then discharges water, the inlet water temperature H1 of the domestic water circuit is lower, while the outlet water temperature H2 of the domestic water circuit is higher. Therefore, Hd1 > Hd2, that is, H1 can be relatively lower than H2, so as to more accurately control the opening of the zero cold water circuit.

[0081] S3. After the water flow finishes circulating in the heating circuit, switch to the domestic water heating circuit and continuously heat the domestic water circuit for the first set time T1.

[0082] Step S3 includes the following steps:

[0083] S31. If H3-H4>Hq, execute step S32, otherwise return to step S2; wherein H3 is the outlet water temperature of the heating circuit detected by the heating outlet water temperature sensor 600, H4 is the outlet water set temperature of the heating circuit, and its value can be designed according to the heating demand; Hq is the set temperature threshold, and its value can be designed according to the actual situation.

[0084] S32, closing the heating circuit to end heating, the controller controls the switching valve 200 to switch to the domestic water heating circuit, and continuously heats the domestic water circuit for the first set time T1.

[0085] In this embodiment, whether to shut down the heating circuit is determined based on the difference between the outlet water temperature H3 of the heating circuit and the set outlet water temperature H4 of the heating circuit. When the difference between H3 and H4 is greater than the set temperature threshold, the water temperature in the heating circuit decreases slightly, and the external heating demand has been met. At this time, the circulation of the heating circuit can be stopped and the heating circuit can be shut down.

[0086] Among them, the first set time T1 can be set according to the actual situation. In this embodiment, the first set time T1 is specifically 1 minute. After the heating circuit ends the cycle, the domestic water heating circuit is forced to start for 1 minute to ensure that the water in the domestic water circuit can be heated to a certain degree, so as to avoid the failure to start zero cold water heating due to the rise of part of the water temperature in the domestic water circuit due to the heat conduction of the heating circuit. Among them, if T1 is too large, it is easy to cause the water temperature in the domestic water circuit to be too high. It has been verified that the best effect is when T1 is 1 minute.

[0087] S4, detecting the water circulation time T in the domestic water heating circuit, if T is greater than the first set time T1 and less than or equal to the second set time T2, executing step S5; if the circulation time of the domestic water heating circuit is greater than the second set time T2, executing step S6;

[0088] The second set time T2 can be set according to actual conditions. In this embodiment, T2 is specifically 2 minutes.

[0089] S5. Detect the water inlet temperature H1 of the domestic water circuit. If H1 satisfies: H1 ≥ H0 - ΔH1, close the domestic water heating circuit; otherwise, return to step S4; wherein ΔH1 is the first stop deviation value.

[0090] When the dual-purpose furnace system 100 is in winter mode, the domestic water heating circuit is forced to heat for the first set time after the heating circuit cycle ends, so as to avoid the domestic water circuit partially heating up due to heat conduction of the heating circuit or uneven heating of the domestic water heating circuit, thereby ensuring that the domestic water circuit can start the zero cold water circulation to heat to a certain temperature, and avoid the zero cold water heating function being unable to start due to the temperature rise of part of the domestic water circuit caused by heat conduction of the heating circuit.

[0091] During the time when T is greater than T1 and less than or equal to T2, it is determined whether to exit zero cold water heating based on the domestic water inlet temperature H1. Since the domestic water inlet temperature H1 is the lowest water temperature in the domestic water circuit and the domestic water inlet temperature H1 meets the demand, the temperature of the domestic water circuit meets the conditions for exiting zero cold water heating. Through the above control method, it is determined whether to exit zero cold water heating based on the heating time and the domestic water inlet temperature, and the zero cold water heating is associated with whether the heating circuit is connected, so as to achieve precise control of zero cold water heating, avoid the influence of the heating circuit on zero cold water heating, and ensure that the temperature of the zero cold water circulation meets the standard.

[0092] S6. Detect the water inlet temperature H1 and the water outlet temperature H2 of the domestic water circuit. If any one of H1≥H0-ΔH1 and H2≥H0+ΔH2 is satisfied, close the domestic water heating circuit; otherwise, return to step S32; wherein ΔH1 is the first stop deviation value, and ΔH2 is the second stop deviation value.

[0093] When the zero cold water heating time T>T2, since the domestic water loop has been heated continuously for a period of time, the water temperature in the domestic water loop is relatively balanced. At this time, only one of the domestic water inlet temperature H1 and the domestic water outlet temperature H2 needs to meet the corresponding set conditions to exit the zero cold water heating, avoiding the domestic water loop from having too high a water temperature, making the zero cold water heating control more accurate and reliable.

[0094] The values ​​of the first deviation ΔH1 and the second stop deviation ΔH2 can be designed according to the actual situation. In this embodiment, the first stop deviation ΔH1 is equal to the second stop deviation ΔH2, that is, the difference between H0 and H1 is equal to the difference between H2 and H0, so as to ensure that the water temperature in the domestic water circuit is relatively uniform. Specifically, the first stop deviation ΔH1 = 5°C, and the second stop deviation ΔH2 = 5°C.

[0095] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A zero cooling water control method for a dual-purpose furnace system, characterized in that: The dual-purpose furnace system includes a heating circuit, a domestic hot water heating circuit, and a domestic hot water circuit. The heating circuit is used to heat the external environment, and the domestic hot water heating circuit is used to heat the water in the domestic hot water circuit; The dual-purpose furnace system has a summer mode and a winter mode. When the dual-purpose furnace system is in the summer mode, the heating circuit is always kept closed; when the dual-purpose furnace system is in the winter mode, the water flow can be switched between the heating circuit and the domestic hot water heating circuit; The zero cold water control method includes the following steps: S1. Determine the mode of the dual-purpose furnace system. If the dual-purpose furnace system is in the winter mode, execute step S2; S2. Determine whether the water flow is circulating in the heating circuit; if so, execute step S3; S3. After the circulation of the water flow in the heating circuit ends, switch to the domestic hot water heating circuit and continuously heat the domestic hot water circuit for the first set time T1; S4. Detect the time T of the water flow circulation in the domestic hot water heating circuit. If T is greater than the first set time T1, execute step S5; S5. Detect the inlet water temperature H1 of the domestic hot water circuit. If H1 satisfies: H1≥H0 - ΔH1, then close the domestic hot water heating circuit; where H0 is the set temperature for zero cold water heating, and ΔH1 is the first stop deviation value; In step S4, if the circulation time of the domestic hot water heating circuit is greater than the second set time T2, then execute the following steps: Detect the inlet water temperature H1 and the outlet water temperature H2 of the domestic hot water circuit. If either H1≥H0 - ΔH1 or H2≥H0 + ΔH2 is satisfied, then close the domestic hot water heating circuit; where ΔH1 is the first stop deviation value and ΔH2 is the second stop deviation value.

2. The zero cooling water control method according to claim 1, characterized in that: In step S4, if T is greater than the first set time T1 and less than or equal to the second set time T2, then execute step S5.

3. The zero cooling water control method according to claim 1, characterized in that: In step S2, if it is determined that the water flow is not circulating in the heating circuit and either H1<H0 - Hd1 or H2<H0 - Hd2 is satisfied, then switch to the domestic hot water heating circuit; otherwise, the domestic hot water heating circuit remains closed; where H1 is the inlet water temperature of the domestic hot water circuit, H2 is the outlet water temperature of the domestic hot water circuit, Hd1 is the first start deviation value, and Hd2 is the second start deviation value.

4. The zero cooling water control method according to claim 3, characterized in that: In step S2, the first start deviation value Hd1>the second start deviation value Hd2.

5. The zero cooling water control method according to claim 1, characterized in that: In step S3, if H3 - H4>Hq, then close the heating circuit and end the heating; where H3 is the outlet water temperature of the heating circuit, H4 is the set outlet water temperature of the heating circuit, and Hq is the set temperature threshold.

6. The zero cooling water control method according to claim 1, characterized in that: In step S1, if the dual-purpose furnace system is in the summer mode, then execute the following steps: If either H1<H0 - Hd1 or H2<H0 - Hd2 is satisfied, then switch to the domestic hot water heating circuit; otherwise, the domestic hot water heating circuit remains closed; where H1 is the inlet water temperature of the domestic hot water circuit, H2 is the outlet water temperature of the domestic hot water circuit, Hd1 is the first start deviation value, and Hd2 is the second start deviation value.

7. The zero cooling water control method according to claim 1, characterized in that: In step S3, the first set time T1 is 1 min.

8. The zero cooling water control method according to claim 1, characterized in that: The first stop deviation value ΔH1 is equal to the second stop deviation value ΔH2.

9. A dual-purpose furnace system, characterized in that: The dual-purpose furnace system applies the zero cooling water control method as claimed in any one of claims 1 to 8.

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